XULA Stats chapter 1

Statistics

the study of how to collect, organize, analyze, and interpret numerical information from data

Descriptive Statistics

collect and organize data

inferential statistics

analyze and interpret data

Individual

a person or object that you are interested in finding out information about.

Variable

The measurement or observation of the individual

Population

set of all values of the variable for the entire group of individuals.

Sample

a subset from the population.

Example of population

All books in the library

Example of sample

50 random books from the libary to asses their genre

Parameter

a number characteristic calculated from the population

Ratio data

diferences between measurements, where true zeros exist

Example of parameter

All US residents who supprt the death penalty

Example of Ratio data

height, age, money

Interval Data

differences between measurements but no true zero

Example of Interval Data

Temperature in Celsius or Fahrenheit, IQ scores

Ordinal data

a type of data that refers solely to a ranking of some kind

Example of Ordinal data

Student letter grade

Nominal Data

Categorical data without a specific order or direction

Example of Nominal Data

Sex

Ethnicity

Marital status

Religious preference

Simple random sampling

every member of the population has an equal probability of being selected for the sample

Nominal quan or qual?

Qualitative

For a set population, does a parameter ever change?

never